US3922853A - Speed control device - Google Patents

Speed control device Download PDF

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Publication number
US3922853A
US3922853A US479181A US47918174A US3922853A US 3922853 A US3922853 A US 3922853A US 479181 A US479181 A US 479181A US 47918174 A US47918174 A US 47918174A US 3922853 A US3922853 A US 3922853A
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US
United States
Prior art keywords
piston
valve
chamber
control device
speed control
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US479181A
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English (en)
Inventor
Hans Kalb
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alstom Power Turbinen GmbH
Original Assignee
AEG Kanis Turbinenfabrik GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by AEG Kanis Turbinenfabrik GmbH filed Critical AEG Kanis Turbinenfabrik GmbH
Application granted granted Critical
Publication of US3922853A publication Critical patent/US3922853A/en
Assigned to ABB TURBINEN NURNBERG GMBH reassignment ABB TURBINEN NURNBERG GMBH ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: AEG KANIS GMBH
Assigned to AEG KANIS GMBH reassignment AEG KANIS GMBH CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). JUNE 19, 1985, GERMANY Assignors: AEG-KANIS TURBINENFABRIK GMBH
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D13/00—Control of linear speed; Control of angular speed; Control of acceleration or deceleration, e.g. of a prime mover
    • G05D13/08—Control of linear speed; Control of angular speed; Control of acceleration or deceleration, e.g. of a prime mover without auxiliary power
    • G05D13/30—Governors characterised by fluid features in which the speed of a shaft is converted into fluid pressure
    • G05D13/32—Governors characterised by fluid features in which the speed of a shaft is converted into fluid pressure using a pump

Definitions

  • the regulating range of the pressure head of the pump is increased by a differential pressure controller, making use of a noz- References Cited zle member, cooperating with a diaphragm and a throttle late.
  • a differential pressure controller making use of a noz- References Cited zle member, cooperating with a diaphragm and a throttle late.
  • the invention relates to a speed control device working with hydraulic fluid and comprising a displacement type pump which serves as signal transmitter of the device. It has been attempted to make use of such a dis placement type pump for speed control devices. Difficulties have been encountered however, because the pressure head of such a pump increases only slightly when the rate of output flow of the pump increases in a linear proportion according to the speed.
  • the pressure head of the pump is ineffective for a use to act directly upon a final control element in order to control a mass flow of an engine.
  • the volumetric slip of a displacement type pump and alterations in the viscosity of a pressure oil may distort the control signal.
  • a speed control device working with hydraulic fluid and including a displacement type pump and comprising an adjustable orifice which is the inlet of a valve chamber that communicates by that orifice with the high pressure side of the pump.
  • the control device comprises further a differential pressure controller comprising a valve forming a first outlet of the valve chamber.
  • the valve comprises a nozzle member and a throttle plate carried by a diaphragm and cooperates with the mouth of the nozzle member which opens into the valve chamber. Further the diaphragm is charged from within the valve chamber by a spring force, which is directed against the throttle plate.
  • the diaphragm and the throttle plate forms one wall of the valve chamber and separates it from a second chamber.
  • This second chamber communicates on the one hand with the high pressure side of the pump by a viscosity dependent throttle and on the other hand with the main outlet of the valve chamber by an adjustable throttling device.
  • the control pressure to actuate the piston of a servo-motor is delivered by the main outlet of the valve chamber.
  • the main advantage achieved by the invention is that no pump of the precision type is required although the exactness of speed control achieved is excellent, whereas the influence of alterations in the viscosity of the hydraulic fluid used is very weak. This is so because the viscosity alterations are compensated for by the viscosity dependent throttle and the adjustable throttle following each other.
  • the intermediate pressure be- 2 tween them actuates the diaphragm and its throttle plate from the other side of the nozzle member.
  • the speed -control device and the servo-motor are integrated in one and the same housing so that the effectiveness of the servo-motor is improved, because the control pressure can directly actuate the piston of the servo-motor.
  • a negative feedback is achieved when the spring, charging the ball of the second valve, is supported by the piston of the servomotor.
  • FIG. 1 is a circuit diagram of the control device according to the invention.
  • FIG. 2 shows the curves of different pressures of the hydraulic fluid in the control device.
  • FIG. 3 is a longitudinal sectional view of the control ler and servo-motor housing.
  • FIG. 4 is a sectional view of an example of an adjustable orifice used in the arrangement according to the invention.
  • FIG. 1 the circuit diagram shows the control device including the displacement type pump 50, the differential pressure controller D, a negative feedback valve RV, the servo-motor SV and a relief pressure and safety valve UV.
  • the main duct 101 leading to the servo-motor charging it with the control pressure p receives pressure oil from the ducts 103, 105 and 106.
  • An adjustable orifice 19 is installed in the duct 106 for setting the rated value of speed, while a throttle 22 and an adjustable throttle 20 are installed in the duct 105.
  • the duct 104 leads from the relief pressure valve UV to the outlet and return duct 102.
  • the pressure in the main duct 101 is specified as p,, the discharge pressure of the pump 50 as p, and the pressure in the return duct 102 as p,,.
  • the pressure oil reservoir 108 is indicated by a dash-dot line.
  • the speed X of the machine to be controlled may be adjusted by a conventional valve (not shown) controlling, for example, the main power duct for fuel in the case of an internal-combustion machine or turbine, or the main steam supply of a steam turbine.
  • the adjusting of the valve is effected by the stem rod 41 of the piston 2 belonging to the servo-motor SV (see FIGS. 1 and 3).
  • FIG. 3 shows the pressure control device and the servo-motor integrated in one housing.
  • the servo-motor comprises a piston 2, biased by a spring 4, and a piston rod 41.
  • the latter can be coupled e.g. with a stem of a valve which governs the flow of elastic fluid of a turbine, and it may be likewise coupled with a valve device adjusting the fuel flow of an internal-combustion machine or a gas turbine.
  • the hydraulic fluid arrives from the high pressure side of the displacement type pump 50, which 3 may be a gear pump, e.g. of the-straight spur or the helical type, to the inlet of a valve chamber 17.
  • the inlet is formed by an adjustable orifice 19 which serves as'the setpoint adjuster for the desired speed of the engine to be controlled.
  • valve chamber 17 depends on the pressure p, in a second chamber separated from the valve chamber 17 by a diaphragm l2 and a throttling plate 14, carried by the diaphragm.
  • the hydraulic fluid arrives in the second chamber 10 through a throttle 22, which is formed by a narrow channel or bore of a certain length so that its throttling effect depends on the viscosity of the hydraulic fluid, since as it is well known, the pressure loss depends on the Reynolds number. In this manner the influence of the viscosity is compensated for.
  • the throttling plate 14 is further biased by a spring 18. It follows from the above that the fluid flow escaping from the valve chamber 17 through the mouth 16 and the bore 13 of the nozzle member decreases by the same ratio as the pressure p, in the second chamber 10 increases. In this manner there is provided a constant difference between the pressure p, in the second chamber 10 and the pressure p, in the valve chamber 17. Consequently there is effected a nearly constant fluid flow through orifice 19. Because the delivery of the pump is, by this means, restricted to be nearly constant too, the pressure head of the pump 50 increases at the same ratio as its shaft revolutions increase with the rotating engine member with which the pump 50 is coupled. The control pressure p which passes from the main outlet 40 of the valve chamber 17 through a channel 31 to the piston chamber 25 where it actuates the piston 2, is increased accordingly.
  • the movement of the piston 2 may then be transmitted to a further regulating device, e.g. a final control valve as described above.
  • a further regulating device e.g. a final control valve as described above.
  • a second throttle is provided which is adjustable.
  • the spring 8 which is supported by the piston 2 and transmits spring forces to the valve ball 6 which are proportional to the movements of the piston 2.
  • a safety valve formed by a ball 29 biased by a spring 30 opens a passageway to the outlet 27, whereby the pump 50 is protected against overload.
  • FIG. 2 it will be explained now how the volumetric slip of the displacement type pump 50 is compensated for.
  • This compensation is effected by the differential pressure controller which generates a pressure p so that the course of the curve p, is steeper than that of the curve p,, the pressure head of the pump 50.
  • a differential pressure p p which diminishes from Ap to Ap proportional to increasing speed, i.e. revolutions of the pump, and ac- 4 cordingly, proportional to increasing movement Y of the final control element.
  • the adjustable orifice 19 shown in detail in FIG. 4 consists of a threaded screw having an incision 61 at its hollow tip 62 which extends into a bore 60.
  • the flow through the bore depends on the position of the incision 61 relative to the bore which can be adjusted by the knurl 65.
  • a ring-seal 63 is provided between two shoulders of the screw.
  • a speed control device working with hydraulic fluid and including a displacement type pump comprising an adjustable orifice being the inlet of a valve chamber that communicates through said orifice with the high pressure side of said pump, and a differential pressure controller including a valve forming a first outlet of said valve chamber, said valve including a nozzle member and a throttle plate carried by a diaphragm and cooperating with the mouth of said nozzle member opening into said valve chamber, the said diaphragm being charged from within the valve chamber by a spring force, the said diaphragm and throttle plate being one wall of said valve chamber separating it from an additional chamber, the additional chamber communicating with the high pressure side of said displacement type pump and with a second, main outlet of said valve chamber through a throttling device, the said main outlet of said valve chamber delivering the control pressure actuating a piston of a servo-motor.
  • Speed control device according to claim 1, wherein said nozzle has a nozzle bore, the outlet of which opposite the nozzle mouth is governed by a second valve.
  • Speed control device wherein said control device and said servo-motor are arranged in one housing, said servo-motor including a piston and a piston rod movable in a piston chamber of said housing, a first part of said piston chamber being the pressure side where the control pressure is actuating the piston, a second part of said piston chamber situated on the other side of said piston being provided with an outlet for the flow-off of pressure oil, the said nozzle bore communicating with said second part of said piston chamber through said second valve, said spring biasing the valve ball being supported by said piston.

Landscapes

  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Control Of Positive-Displacement Pumps (AREA)
  • Control Of Turbines (AREA)
  • Control Of Fluid Gearings (AREA)
  • Control Of Velocity Or Acceleration (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Control Of Fluid Pressure (AREA)
US479181A 1973-06-15 1974-06-13 Speed control device Expired - Lifetime US3922853A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2331282A DE2331282C3 (de) 1973-06-15 1973-06-15 Einrichtung zur Drehzahlregelung

Publications (1)

Publication Number Publication Date
US3922853A true US3922853A (en) 1975-12-02

Family

ID=5884485

Family Applications (1)

Application Number Title Priority Date Filing Date
US479181A Expired - Lifetime US3922853A (en) 1973-06-15 1974-06-13 Speed control device

Country Status (4)

Country Link
US (1) US3922853A (ja)
JP (1) JPS5838805B2 (ja)
DE (1) DE2331282C3 (ja)
GB (1) GB1463716A (ja)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108311931A (zh) * 2018-02-02 2018-07-24 苏州辰晟优机电科技有限公司 一种通用打孔机构
US10184476B2 (en) 2014-03-26 2019-01-22 Wilo Se Method of determining hydraulic operating point of a pump

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2729512A1 (de) * 1977-06-30 1979-01-11 Bosch Gmbh Robert Steuereinrichtung fuer ein hydrostatisches getriebe
DE3007788A1 (de) * 1980-02-29 1981-09-17 Linde Ag, 6200 Wiesbaden Anordnung von hydraulischen widerstaenden und anordnung zum erzeugen eines drehzahlabhaengigen signales

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2005731A (en) * 1930-06-16 1935-06-25 Cincinnati Milling Machine Co Viscosity compensating system
US2111964A (en) * 1932-10-12 1938-03-22 Western Electric Co Liquid flow control system
US2456431A (en) * 1940-11-08 1948-12-14 Landis Tool Co Valve means to compensate for viscosity in hydraulic systems
US3392633A (en) * 1966-10-21 1968-07-16 Caterpillar Tractor Co Overridable check valve mechanism

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2005731A (en) * 1930-06-16 1935-06-25 Cincinnati Milling Machine Co Viscosity compensating system
US2111964A (en) * 1932-10-12 1938-03-22 Western Electric Co Liquid flow control system
US2456431A (en) * 1940-11-08 1948-12-14 Landis Tool Co Valve means to compensate for viscosity in hydraulic systems
US3392633A (en) * 1966-10-21 1968-07-16 Caterpillar Tractor Co Overridable check valve mechanism

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10184476B2 (en) 2014-03-26 2019-01-22 Wilo Se Method of determining hydraulic operating point of a pump
CN108311931A (zh) * 2018-02-02 2018-07-24 苏州辰晟优机电科技有限公司 一种通用打孔机构
CN108311931B (zh) * 2018-02-02 2018-12-11 浙江当代风机有限公司 一种液压驱动的通用打孔机构

Also Published As

Publication number Publication date
JPS5838805B2 (ja) 1983-08-25
JPS5076601A (ja) 1975-06-23
DE2331282B2 (de) 1977-09-08
DE2331282C3 (de) 1978-04-20
GB1463716A (en) 1977-02-09
DE2331282A1 (de) 1975-01-16

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Legal Events

Date Code Title Description
AS Assignment

Owner name: AEG KANIS GMBH

Free format text: CHANGE OF NAME;ASSIGNOR:AEG-KANIS TURBINENFABRIK GMBH;REEL/FRAME:005237/0583

Effective date: 19891204

Owner name: ABB TURBINEN NURNBERG GMBH, GERMANY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:AEG KANIS GMBH;REEL/FRAME:005237/0587

Effective date: 19891204